The invention relates to a process for producing a ceramic-metal substrate for electrical circuits.
Production of a metal coating necessary for producing printed conductors, terminals, etc., on a ceramic using the so-called DCB process (direct copper bond technology) is known. Copper foils are oxidized on their surfaces and form the metal coating. The copper oxide layer of these foils forms a eutectic with a melting point below the melting point of the copper, so that by applying the foils to the ceramic and by heating all the layers they can be joined to one another, by melting on the copper in the area of the oxide layer. The DCB process is a technique known to one skilled in the art which has the following process steps:
oxidation of a copper sheet such that a uniform copper oxide layer forms; PA1 placing the copper sheet on the ceramic layer; PA1 heating the combination to roughly 1071.degree. C., for example; PA1 cooling to room temperature.
The object of the invention is to devise a production process with which it is possible to produce metal-ceramic substrates for electric power circuits economically and also with optimum thermal properties.